Made overlays thread safe for write operations, which solved a script
crash.
Added some missing locks to make Overlays thread safe for reading as well.
Use local viewer model for specular.
Added a new lock specific to deleting, and improved safety
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
added if to not track ParticleErase packets
removed updatePacketTimestamp()

..from OctreeQueryNode
added flag,seq,ts to ParticleErase and ModelErase

... this fixes unreasonable flight-time issue
added flag,seq,st to EnvironmentData, untested

removed/commented out debug prints
Merge remote-tracking branch 'upstream/master'
removed debug info, cleaned code for pull req
removed debug stuff i missed
updated packet type version numbers
moved _sequenceNumber back to OctreeQueryNode
removed _sequenceNumber from OctreeSendThread

inlined getSequenceNumber and incrementSequenceNumber
removed duplicate function bodies
Merge pull request #2950 from wangyix/flighttime_fix_pull

Fix for unreasonable flight times